用括号内所给单词的适当形式填空，每空格限填一词。
1.We can see many
(potato) in the supermarket.
2.My grandparents live on the
(nine) floor of a tall building.
3.If at first you don't
(success), try, try again.
4.
(lucky), Fred was not hurt in the car accident.
5.They have invited a (science) to give them a speech on space.
6.Eating vegetables every day makes us (healthy) than before.
